If you want to host the custom ComboBox control in a single grid cell, then you can do this by setting the celltype of the cell to be a control and then set the control that you want the cell to be associated with. Below is the code.

If you want to havethe custom ComboBox control in several cells, then you will have to create a custom celltype deriving the control. It requires a model class and a renderer class. The model class handles the serialization requirements for the control and creates the renderer class. The renderer class handles the UI requirements of the cell.

Please refer to the following shipped browser sample for more details.[install drive]\Syncfusion\Essential Studio\4.4.0.49\windows\Grid.Windows\Samples\CustomCellTypes\DerivedCellControlTutorial\[install drive]\Syncfusion\Essential Studio\4.4.0.49\windows\Grid.Windows\Samples\CustomCellTypes\DropDownFormAndUserControlSample\